The mesh architecture is a spanning tree that extends from the Root Access Point (RAP). A spanning tree is built by the RAP by advertising in the beacon that it intends to form a tree. The Mesh Access Points (APs) join this spanning tree by processing mesh beacons that are generated by the RAP. In the current scheme, the APs follow the RAP beacons to join the tree on the same frequency band and channel that the beacon is advertised on. So, when the RAP cannot use this frequency band and channel due to a radar event or a hardware failure, the Mesh Access Points (MAPs) do not receive the beacons any longer and they disconnect from the tree.
Another problem is that some wireless mesh networks, for examples those that are working in the 5 G DFS (5 Gigahertz Dynamic Frequency Selection) domain, may be required to move off channel when radar is detected. Moving off channel is inherently disruptive in DFS domains because the new channel requires a channel availability check (waiting for 60 seconds of silence) before an AP can transmit on the new channel. Meanwhile LWAPP (Lightweight Access Point Protocol) connections can time out and/or the routing tree can time out, disrupting data forwarding. Moreover, “false” radar detection further exacerbates the radar problem, creating unpredictable and unstable service.